Air to Water Harvest

Comparison of Dew yields in four Mediterranean sites: Similarities and Differences M. Mileta, etc – Great review of black body radiant chilling based water from air. We at Air Solar Water built a series of systems using a similar premise and were able to reliably deliver over 10F chilling at night. This was adequate to deliver water in some locations but ultimately we found that it was unreliable in dry climates where 10F of chilling was inadequate to reliably reach the dew point. Still this area of research holds promise because it can be used to pre-chill air entering the absorption chamber by up-to 10F which increases the relative humidity and can increase the humidity available to absorb into the desiccant. In practice this is challenging because the sky facing chilling panels can compete for space with solar heat collection panels. Another possible use of this technique is aiming specialized heat exchangers to the north sky. In desert climates we found it possible to deliver over 12F chilling compared to ambient which can be used to help drive condensation and drive convective air flows. Since only a view of the north sky is required it can be engineers to exist in the shade of solar collectors with less competition for space. http://www.up.ac.za/academic/geog/meteo/EVENTS/fogdew2003/PAPERS/C69.pdf

http://news.bbc.co.uk/1/hi/uk/4674206.stm -Dry January as drought continues – England and Wales have had the driest January since 1997 and the sixth driest on record.

Long dry sucks life out of land. June was the driest on record for Western Australia, the third-driest for Victoria and the fifth-driest nationwide. Sydney Australian, Australia. 13 July 2006. http://www.theaustralian.news.com.au/story/0,20867,19768883-30417,00.html

Big dry may spell tougher restrictions on water use. Tougher water restrictions could come into force as early as next month as Victoria continues to experience one of its driest periods on record. Melbourne Age, Australia. 10 July 2006.
http://www.theage.com.au/news/national/big-dry-may-spell-tougher-restrictions-onwater-use/2006/07/09/1152383611839.html

http://news.bbc.co.uk/1/hi/uk/4674206.stm -Dry January as drought continues – England and Wales have had the driest January since 1997 and the sixth driest on record. v Long dry sucks life out of land. June was the driest on record for Western Australia, the third-driest for Victoria and the fifth-driest nationwide. Sydney Australian, Australia. 13 July 2006. http://www.theaustralian.news.com.au/story/0,20867,19768883-30417,00.html

Desalination

Desalination is a critical technology that when combined with Water saving technology, Water reclamation and ground water represent the major competition for Atmospheric Water generators.

A comprehensive list of desalination articles and projects http://www.waterwebster.com/Desalination.htm

Wikipedia Desalination defined with several good links http://en.wikipedia.org/wiki/Desalination

Water policy Desalination state of the industry report 2005-2008 Review of the Current State of Desalination Water Policy Working Paper 2005-008 Prepared by: Ulrich Ebensperger and Phyllis Isley, Ph.D. 1 http://www.h2opolicycenter.org/pdf_documents/water_workingpapers/2005-008.pdf

Water Desalination Market Acceleration. Worldwide, only 1% of drinking water is produced by desalination, supplied by more than 12 500 plants in more than 120 countries. The market volume has soared from $ 2.5 billion in 2002 to $ 3.8 billion in 2005 with a growth rate of over 15% per annum (plant and equipment, not considering the whole value chain). The market worldwide should reach nearly $ 30 billion by 2015. http://ec.europa.eu/environment/etap/pdfs/watedesalination.pdf

Israeli project 100 million m³ cost $250 million with liability for an additional $825 million to the partner /
vendor for a total cost of 1.075 billion. This equates to 72.38 million gallons per day for a capital cost of 14.848 million per million gallons per day or 148.5 million dollars for a 10 million gallons per day.
http://www.water-technology.net/projects/israel/

Larnaca SWRO Water Desalination Plant, Cyprus produces 54,000m³/day (14,265,290 gallons) cost $47 million which equals 3.294 million per million gallons per day or 32.95 million per 10 million gallons per day. http://www.water-technology.net/projects/larnaca/

DESALINATION, WITH A GRAIN OF SALT — A CALIFORNIA PERSPECTIVE California Water Desalination Task Force Desalination Technology Working Paper 9/15/03 – was used to supply many of the energy consumption and market sizing numbers for this research. It’s numbers seem to be consistent with several other reports. .5 kwh/m3 (14 kwh/1000 gallons) – 2001. Yields 14 watts per gallon or 140,000 KWh per day for a 10 MGPD facility. Have seen numbers as low as 10 watts per gallon but no installed plant that claims to deliver this from ocean water. DESALINATION – PRODUCING POTABLE WATER Shows a range of 8 watts to 36 watts per gallon http://resources.ca.gov/ocean/97Agenda/Chap5Desal.html

California Water Desalination Task Force Desalination Technology Working Paper 9/15/03 http://www.pacinst.org/reports/desalination/desal_exec_summ.pdf. – was used to supply many of the energy consumption and market sizing numbers for this research. It’s numbers seem to be consistent with several other reports. .5 kwh/m3 (14 kwh/1000 gallons) – 2001. Yields 14 watts per gallon or 140,000 KWh per day for a 10 MGPD facility. Have seen numbers as low as 10 watts per gallon but no installed plant that claims to deliver this from ocean water. – This report shows solar stills at 0.1 gallons per day per sq foot. The wave based system takes advantage of a much higher energy density available in the waves and the fact that the water has already absorbed environmental heat energy. Our test unit at 10 foot by 8 foot or 80 sq foot is nominally rated at 200 gallons per day which is 2.5 gallons per sq foot which is 25 times higher than what is delivered from the solar still.

California Water Plan Update 2005 Volume 2 chapter 6 – Page #7 shows an average $800 to $2000 per acre foot produced from current state desalination. This converts to $2.46 to $6.15 cents per 1000 gallons. Our preliminary estimates show that when implemented in municipal scales the wave based system could compete in the lower ½ of this range.http://www.waterplan.water.ca.gov/docs/cwpu2005/vol2/v2ch06.pdf

Marin Water district in California shows historical energy costs per 1,000 gallons at 30.7 KWh down to
emergent technologies at 7.15Kw when using less salty bay water. In latter slides they show a budget of 10KWh per 1,000 gallons which is consistent with the Texas statistics. Also includes land area calculations for PV and wind energy. http://www.marinwater.org/documents/Desal_Energy_Use_Seminar_c.pdf

Drought, gales and refugees: what will happen as UK hots up Saturday July 22, 2006 The Guardian Summers could be 25% drier across England, 10%-15% drier in Scotland. Could lower world wide DGP by up to 20% References G8 report http://www.guardian.co.uk/climatechange/story/0,,1826470,00.html

Temperature set to hit 100 degrees – and global warming is to blame. With the mercury expected to approach 100F (37.8C) for only the 2nd time in Britain’s history – but also the 2nd time in under 3 years – researchers said the unusual heat was entirely consistent with predictions of climate change London Independent, England. 19 July 2006.

Potential Effects of Climate Change on New Mexico. The purpose of the report is to assess the potential impacts on New Mexico. of climate change that could be brought about by global warming http://www.nmenv.state.nm.us/cc/Potential_Effects_Climate_Change_NM.pdf

Global warming intensifying drought patterns: CSIRO Last Update: Monday, October 16, 2006. 3:23pm (AEST) There’s been more rain, but droughts have lengthened. an accelerating shift in climate will bring warmer temperatures, as well as more periods of intense rain and longer dry spells to some areas. San Antonio has experienced six of the seven warmest months have occurred since 1880. http://www.abc.net.au/news/newsitems/200610/s1765929.htm

Global Warming Will Alter Character of the Northeast Leading Scientists Say How We Manage Emissions Today Will Dramatically Affect Changes in Northeast Climate and Quality of Life http://www.ucsusa.org/news/press_release/global-warming-will-alter.html

Scientists Urge Rapid Action on Global Warming By CRAIG R. WHITNEY, SPECIAL TO THE NEW YORK TIMES LEAD: A panel of scientists warned today that unless emissions of carbon dioxide and other harmful gases were immediately cut by more than 60 percent, global temperatures would rise sharply over the next century, with unforeseeable consequences for humanity. May 26, 1990 World News http://select.nytimes.com/gst/abstract.html?res=F3061FF73E5B0C758EDDAC0894D8494D81&n=Top%2fNews%2fScience%2fTopics%2fGlobal%20Warming

Global warming intensifying drought patterns: CSIRO Last Update: Monday, October 16, 2006. 3:23pm (AEST) There’s been more rain, but droughts have lengthened. an accelerating shift in climate will bring warmer temperatures, as well as more periods of intense rain and longer dry spells to some areas. San Antonio has experienced six of the seven warmest months have occurred since 1880. http://www.abc.net.au/news/newsitems/200610/s1765929.htm

Global Warming Will Alter Character of the Northeast Leading Scientists Say How We Manage Emissions Today Will Dramatically Affect Changes in Northeast Climate and Quality of Life http://www.ucsusa.org/news/press_release/global-warming-will-alter.html

Scientists Urge Rapid Action on Global Warming By CRAIG R. WHITNEY, SPECIAL TO THE NEW YORK TIMES LEAD: A panel of scientists warned today that unless emissions of carbon dioxide and other harmful gases were immediately cut by more than 60 percent, global temperatures would rise sharply over the next century, with unforeseeable consequences for humanity. May 26, 1990 World News http://select.nytimes.com/gst/abstract.html?res=F3061FF73E5B0C758EDDAC0894D8494D81&n=Top%2fNews%2fScience%2fTopics%2fGlobal%20Warming

Carbon Dioxide / Greenhouse gas emissions

The USA department of energy show 1.2 pounds of Carbon per KWh consumed.
http://www.energystar.gov/index.cfm?c=energy_awareness.bus_energy_use

Carbon Dioxide Emissions from the Generation of Electric Power in the United States July 2000 Department of Energy Washington, DC 20585 Environmental Protection Agency Washington DC 20460 – Page #6 Table 1 shows the best case emissions of 1.3 pounds carbon per Kwh consumed. A earlier report showed 1.2 pounds of carbon and some califonri reports show an average of 0.86 pounds however California is shifting more heavily to natural gas away from Hydro to meet increasing demands their emissions per Kwh is likely to grow to match national averages. We used 1.2 pounds to ensure our calculations where conservative http://www.eia.doe.gov/cneaf/electricity/page/co2_report/co2report.html

The USA department of energy show 1.2 pounds of Carbon per KWh consumed. http://www.energystar.gov/index.cfm?c=energy_awareness.bus_energy_use

U.S. EPA – Useful Facts & Figures facts and figures for raising awareness of energy use. All facts and figures are from U.S. EPA. http://www.energystar.gov/index.cfm?c=energy_awareness.bus_energy_use

Dehumidifiers

Dehumidifiers are similar to atmospheric water generators in the both remove humidity from air. Dehumidifiers can generally be classified as refrigeration based and desiccant based. The refrigeration based systems are easy to understand and widely available but have high relative operating and energy costs and struggle to perform well in areas with low temperature or low humidity. Desiccant systems tend to be heavier, larger and more expensive mostly due to low production volumes but they can be optimized to produce much lower humidity and when properly engineered can operate with lower energy costs. Dehumidifiers can either produce liquid water or vent a humidity enriched gas stream which can allow more efficient operation. The Air Solar Water system and process can be readily adapted to operate as a dehumidifier.

Dessicants Calcium Chloride, Lithium Chloride, Lithium Brohmide

Desiccants and drying agents allow a system to absorb water from the air which can then be converted to liquid water by later extracting the water in the form of vapor which can be concentrated and condensed as liquid water. The Air solar water system uses proprietary desiccant system that is modified to meet specific requirements of various locations because some desiccants perform better at high humidity while others offer better relative performance at lower humidity.

Pyhsics & Heat Engines

Heat engines able to capture working energy or electrical energy from thermal delta are interesting because they could provide part or all of the electrical energy needed by the Air solar Water process. In addition some heat engines can also operate as heat pumps which can be used to increase thermal delta across the condenser and cooling or to better harvest ambient heat from the environment. As a practical matter we have found the production costs of these machines to be sufficiently high that it has been more cost effective to use photo voltaic power but this is an area with remaining promise.

Thermo-electric generators convert heat directly into electricity, using the voltage generated at the
junction of two different metals. http://www.dself.dsl.pipex.com/MUSEUM/POWER/thermoelectric/thermoelectric.htm

ENECO has developed the Thermal Chip, a new type of semiconductor device for direct energy conversion, which means it converts one form of energy to another without intermediate steps or moving parts. http://www.eneco.com/technology.html

Power Chips™ Convert Heat to Electricity – Chips use thermionics to convert heat directly into electricity
with a Carnot heat pump efficiency of up to 70-80%. This will be one of the first industrial applications of
nanotechnology. http://www.powerchips.gi/

Compression Costs

Compression and closely associated relative vacuum can be used as a mechanism to pump heat from one gas stream into another gas stream. This can be driven by mechanical energy or by thermal expansion / contraction causing compression of associated gas volumes. In scenarios where mechanical energy is available compression can be used improve the efficiency or operating range of critical heat exchange / condenser elements.

Insolation

http://www.solar4power.com/solar-power-insolation-window.html

On line daily insolation calculator but the units seem to be wrong. I use this to lookup the lat, lon for each city then use the Nasa link below get the details for that location. http://www.wunderground.com/calculators/solar.html

Calculate insolation daily average with sunrise and sunset. Must take these numbers multiply by 2 and then divide by hours of (daylight -2) to arrive at average sunlight intensity during primary solar day. http://aom.giss.nasa.gov/srlocat.html